CS259285B1 - Method of liquid nitrogen-sulphuric fertilizers production - Google Patents

Abstract

The solution relates to the process of nitrogen-sulfur production fertilizers based on nitrate and sulphate ammonium, urea and water. cause the production of ammonium sulphate solution sulfuric acid preferably from the production of methyl methacrylates neutralizes ammonium nitrate. Before, during, or after neutralization urea and urea are added possibly also ammonium nitrate, ammonium sulfate and ammonia.

Description

The invention relates to a process for the production of liquid nitrogen-sulfur fertilizers based on nitrate and ammonium sulphate, urea and water.

Nitrogen fertilizers are a significant burden for the economy of the CSSR from the energy and foreign exchange point of view, because we import the crucial raw materials for their production. Sufficient ammonium sulphate is available from domestic sources of nitrogen fertilizers as a by-product mainly from the production of caprolactam. Despite its suitability for certain crops, especially in pre-sowing bases and on alkaline grounds, ammonium sulphate is less interested in agricultural practice than is a real offer. Its more effective use is also conditional on the socially desired increase in the production of some major products (caprolactam, ferrous pigments, methyl methacrylates).

In view of the above-mentioned energy intensity of the production of nitrogen fertilizers, the use of ammonium sulphate as a by-product in agriculture is of particular importance. Globally, ammonium sulphate is used as a fertilizer mainly in tropical regions of Asia, Africa, Central and South America. In a humid) tropical climate, its important pre-

% N T ° C SET 260 20.5 -23 260 20.5 <-15 286 22.5 <-15 310 24.2 <-15

low hygroscopicity. It is also widely used in sulfur-deficient areas and in the cultivation of crops favorably responsive to sulfur fertilization ('Ammonium sulphate-past, present and future', Nitrogen No. 141, January— —February 1983).

The condition for successful use of ammonium sulphate in agricultural practice and Czechoslovakia is the search for such forms and ways of its use, which minimize some of its negative properties, especially the relatively lower content of nutrients, less suitable application form (finely crystalline product) and especially high physiological acidity. Long-term use of ammonium sulfate and insufficient liming significantly deteriorates the physical-chemical properties of soils.

Liquid - solution and suspension fertilizers are the most suitable production and application forms of fertilizers. The suitability of the form eliminates the reduction of the total nitrogen concentration in the product when incorporating ammonium sulfate into liquid fertilizers. It is known abroad to produce fertilizer types based on urea, ammonium nitrate and ammonium sulphate. Among the many options we list the following types:

% Urea% NH1NO3% (NH3) zSOj

25.7 10.0 23.9 23.2 14.5 21.7 28.5 13.3 22.2 29.1 20.0 18.2

Compared to the solution fertilizer DAM 390 produced by us, these fertilizers are characterized by higher phase stability (up to –23 ° C), increased proportion of ammoniacal nitrogen and enable especially effective utilization of ammonium sulphate, whose supply in crystalline form exceeds the demand of agricultural practice. . Ammonium sulphate in Czechoslovakia originates mainly as a by-product in the production of caprolactam and methyl methacrylates. The acid leachate produced from the process is neutralized with ammonia, concentrated and ammonium sulphate is obtained by crystallization. In particular, significant energy savings can be obtained in the treatment of acid waste liquors into SADAM type liquid fertilizers according to the invention. SUMMARY OF THE INVENTION The present invention relates to a process for the production of liquid nitrogen-sulphate fertilizers based on nitrate and ammonium sulphate, urea and water, characterized in that the neutralization reaction is carried out. is subjected to a solution of ammonium sulphate in sulfuric acid with ammonium nitrate ammonium nitrate, wherein urea is added to the reaction mixture before, during or after the neutralization reaction and optionally also nitric acid and / or ammonium nitrate, and / or ammonium sulphate, and / or ammonia.

In the context of the process according to the invention, it has proven to be particularly advantageous to use as by-products ammonium sulphate in sulfuric acid sulfuric by-products from the production of methyl methacrylate ^? and / or from the manufacture of caprolactam.

From an economic and operational point of view, it appears appropriate to use ammonium nitrate ammonium nitrate of the following composition for neutralization:

il ’

53.5 - 64.5% by weight · NH 4 NO 3

18.8 - 27.2% NH ₃

14.3 - 21.7% by weight of H ₂ O.

It has been experimentally confirmed that urea can be added to the reaction system in the solid state, in the form of a melt, or in the form of an aqueous solution.

The advantage of the proposed solution is the significant energy savings and the possibility of production in the ČSSR of hitherto not produced types of liquid fertilizers after the modification and completion of machinery and technological equipment in the existing ammonium sulphate plants.

The addition of urea in the form of a melt, respectively. solution, it is possible to achieve further significant energy savings during crystallization, respectively. prilled.

The necessary raw materials - urea and ammonium nitrate ammonium nitrate are from domestic production and their transport, storage and dosing into the technological process is mastered. In n. p. Two types of ammonium nitrate ammonium nitrate are currently produced. Called. summer ADA of the following composition:

NH4NO3 - 63.0 ± 1.5%;

H2O - 17.0 + 2.7%;

NH 3 - 20.0 + 1.2%;

crystallization point - about 0 ° C and winter type ADA composition:

NH 4 NO 3 - 55.0 + 1.5%;

H2O - 19.0 + 2.7%;

NH 3 - 26 + 1.2 ° / o;

crystallization point - approx. - 31.7 ° C.

According to the findings (Prof. Fecenko, DrSc., VŠP Nitra, Ing. Synak, CSc., VÚCHT Bratislava) there are no organic substances (such as residues from caprolactam or methyl methacrylate production) present in the product, phytotoxic and easily degraded in the subsoil .

The following examples illustrate the invention but do not limit it in any way.

Example 1

In a 3-1 sulfonation flask, 100 parts by weight of an acidic waste solution from methyl methacrylate production (after distillation of low-boiling organic fractions) of 43.2% H2SO1, 5.69% N-ammoniacal and 2.17% organic, was neutralized with 41 parts by weight Ammonium nitrate (ADA summer type) of 19.8% NH3, 62.2% NH4NO3 and 18% H2O were added to the system, 2.5 parts by weight of ammonium sulfate, 65 parts by weight of granular urea and 46 parts by weight of water were added. a liquid fertilizer of the SADAM 260 type having the following composition was obtained:

39.62% water,

Claims (5)

SUBJECT 1. A process for the production of liquid nitric sulfur fertilizers based on nitrate and ammonium sulphate, urea and water, characterized in that the neutralization reaction is subjected to a solution of ammonium sulphate in sulfuric acid with ammonium nitrate ammonium nitrate, the reaction mixture being before, during the neutralization reaction. or add urea after completion. 2. Process according to claim 1, characterized in that nitric acid and / or ammonium nitrate and / or ammonium sulphate and / or ammonia are added to the reaction mixture. 3. The method of manufacture referred to in point 1, characterized by 23.91% ammonium sulfate, 10.04% ammonium nitrate, 25,58% urea, 0.85% organic matter, total N = 20.42%, pH = 6.38, = 1.268 g / cm ³ . Example 2 To 100 parts by weight of a waste solution of the same composition as Example 1, 8.0 parts by weight of 55% HNO 3 were added and neutralized with 47 parts by weight of ADA-1-year type with the addition of 74.5 parts by weight of urea and 35.5 parts by water. Cooling the reaction mixture to room temperature yielded a liquid nitrogen-sulfur fertilizer of the SADAM 286 type having the following composition: 35.70% water, 22,10% ammonium sulphate, 13.20% ammonium nitrate, 28.20% urea 0.82% organic matter, total content N - 22.43% / o; pH = 6.52. EXAMPLE 1 a d 3 100 parts by weight of waste acid corresponding to the composition of Example 1 were neutralized with 31 parts of ADA-winter type, the composition: 25.4% NH3 55.3% NH4NO3 19.3% H2O. 7 parts of ammonium nitrate and 64 parts of urea and 50 parts of water were added to the neutralization mixture. SADAM 260 fertilizer of the following composition was obtained: 42.0% water, 23.5% ammonium sulphate, 9.8% ammonium nitrate 25,9% urea, 0.88% organic compounds, total N = 20.39%; pH = 6.52; = 1.265 g / cm ³ . YNALEZ, characterized in that it contains ammonium nitrate ammonia 53.5 to 64.5 wt. ammonium nitrate, 18.8 to 27.2 wt. % ammonia, 14.3 to 21.7 wt. water. 4. The process of claim 1 wherein the ammonium sulfate and sulfuric acid solutions are from methyl methacrylate production. 5. The process of claim 1 wherein the urea is added in the solid state, in the form of a melt or in the form of an aqueous solution.